Implantable medical device employing integral housing for a formable flat battery

Abstract

A body implantable medical device (IMD) includes a first shell and a second shell whose outer surfaces are biocompatible. The IMD further includes a battery enclosure defined by a cover and all or a portion of the first shell of the IMD housing. The cover of the battery enclosure is disposed between the inner surfaces of the first and second shells and has a greater rigidity than the first shell. An electrochemical cell, such as a flat liquid electrolyte battery, is provided in the battery enclosure. Electronic circuitry, supported on a flexible wiring substrate, is provided between the inner surface of the second shell and the cover of the battery enclosure. A hermetic seal is provided between the cover of the battery enclosure and all or a portion of the first shell. The hermetic seal is preferably a weld joint, such as a butt, spank or standing edge weld joint.

What is claimed is:  
     
       1. A selectively deformable housing assembly for an implantable medical device, comprising: 
       a housing comprising a first shell and a second shell, the first and second shells comprising an inner surface and an outer surface, respectively, the outer surfaces of the first and second shells comprising a material compatible with body fluids;  
       a battery enclosure comprising a cover and all or a portion of the first shell of the housing assembly, the cover of the battery enclosure disposed between the inner surfaces of the first and second shells, wherein said cover has a greater thickness dimension or a higher modulus of elasticity than the first shell and an insulated electrical conductor sealingly coupled therethrough;  
       an electrochemical battery cell including an anode member, a cathode pellet and a liquid electrolyte disposed in the battery enclosure;  
       an operable electronic circuit electrically coupled to the electrochemical battery cell, electrically coupled to a medical electrical lead, and wherein said operable electronic circuit is mechanically coupled between the inner surface of the second shell and the cover of the battery enclosure and a majority of the operable electronic circuit is coupled to a deformable, flexible circuit substrate; and  
       a hermetic seal isolating the battery enclosure.  
     
     
       2. The deformable housing assembly of  claim 1 , wherein the thickness dimension of the cover is approximately double the thickness of the first shell. 
     
     
       3. The deformable housing assembly of  claim 1 , wherein the first and second shells are fabricated from surgical Grade I Titanium. 
     
     
       4. The deformable housing assembly of  claim 3 , wherein the electrochemical battery cell further includes a lithium anode, a cathode pellet with Li/CSVO/CF x  chemistry and a liquid electrolyte of type 1M LiBF y  in GBL/DME. 
     
     
       5. The deformable housing assembly of  claim 4 , wherein the liquid electrolyte is type 1 N LiAsF 6  in PC/DME with Li/CSOV chemistry. 
     
     
       6. The deformable housing assembly of  claim 5 , wherein the liquid electrolyte is a one of the following: Li/MnO 2 , Li/SVO, Li/CF x , or Li/SVO—CF x . 
     
     
       7. The deformable housing assembly of  claim 1 , further including a feedthrough assembly coupling the battery enclosure to the operable electronic circuit, the feedthrough assembly disposed in a hermetically sealed aperture of the cover and further including a ferrule and a feedthrough pin electrically isolated from each other by a sealing glass. 
     
     
       8. The deformable housing assembly of  claim 7 , wherein the feedthrough pin is constructed from a one of the following materials: Nb, Ni, Ti, Mo, or Ta; 
       wherein the sealing glass is a one of the following: 9013 glass, CABAL-12, or Ta-23 glass; and  
       wherein the ferrule is constructed from a one of the following materials: MP-35N, 304L stainless steel or titanium 6-4.  
     
     
       9. The deformable housing assembly of  claim 1 , further comprising: 
       an antenna coupled to the deformable, flexible substrate.  
     
     
       10. The deformable housing assembly of  claim 9 , wherein the antenna is embedded into the deformable, flexible substrate. 
     
     
       11. The deformable housing assembly of  claim 1 , wherein the implantable medical device is one of the following: a pacemaker, a monitoring device, a nerve stimulator, a pacemaker/cardioverter/defibrillator, or an implantable cardioverter/defibrillator. 
     
     
       12. The deformable housing assembly of  claim 1 , wherein the cover has regions of different elevation and at least one of the regions defines a recessed region between the cover and the second shell. 
     
     
       13. The deformable housing assembly of  claim 1 , wherein the battery enclosure has a maximum thickness of approximately 0.135 inches. 
     
     
       14. The deformable housing assembly of  claim 1 , wherein the housing is further defined by a perimeter, the perimeter having a significant curvilinear portion. 
     
     
       15. A selectively deformable housing assembly for an implantable medical device, comprising: 
       a housing comprising a first shell and a second shell, the first and second shells comprising an inner surface and an outer surface, respectively, the outer surfaces of the first and second shells comprising a material compatible with body fluids, the first shell comprising a substantially straight peripheral wall portion;  
       a battery enclosure comprising a cover and all or a portion of the first shell of the housing assembly, the cover of the battery enclosure disposed between the inner surfaces of the first and second shells, wherein said cover comprises a coined edge and has a greater thickness dimension or a higher modulus of elasticity than the first shell, and an insulated electrical conductor sealingly coupled therethrough;  
       an electrochemical battery cell including an anode member, a cathode pellet and a liquid electrolyte disposed in the battery enclosure;  
       an operable electronic circuit electrically coupled to the electrochemical battery cell, electrically coupled to a medical electrical lead, and wherein said operable electronic circuit is mechanically coupled between the inner surface of the second shell and the cover of the battery enclosure and a majority of the operable electronic circuit is coupled to a deformable, flexible circuit substrate; and  
       a hermetic seal comprising a butt weld joint between the coined edge of the cover and the substantially straight peripheral wall portion of the first shell.  
     
     
       16. A selectively deformable housing assembly for an implantable medical device, comprising: 
       a housing comprising a first shell and a second shell, the first and second shells comprising an inner surface and an outer surface, respectively, the outer surfaces of the first and second shells comprising a material compatible with body fluids, the first shell comprising a spanked edge;  
       a battery enclosure comprising a cover and all or a portion of the first shell of the housing assembly, the cover of the battery enclosure disposed between the inner surfaces of the first and second shells, wherein the cover comprises a peripheral edge and has a greater thickness dimension or a higher modulus of elasticity than the first shell, and an insulated electrical conductor sealingly coupled therethrough;  
       an electrochemical battery cell including an anode member, a cathode pellet and a liquid electrolyte disposed in the battery enclosure;  
       an operable electronic circuit electrically coupled to the electrochemical battery cell, electrically coupled to a medical electrical lead, and wherein said operable electronic circuit is mechanically coupled between the inner surface of the second shell and the cover of the battery enclosure and a majority of the operable electronic circuit is coupled to a deformable, flexible circuit substrate; and  
       a hermetic seal comprising a spank weld joint between the peripheral edge of the cover and the spanked edge of the first shell.  
     
     
       17. The deformable housing assembly of  claim 16 , wherein the first shell further comprises a first substantially straight peripheral wall portion and a second substantially straight peripheral wall portion adjacent the first substantially straight peripheral wall portion and being offset relative to the first substantially straight peripheral wall portion, the first substantially peripheral wall portion defining a ledge which the peripheral edge of the cover engages. 
     
     
       18. A selectively deformable housing assembly for an implantable medical device, comprising: 
       a housing comprising a first shell and a second shell, the first and second shells comprising an inner surface and an outer surface, respectively, the outer surfaces of the first and second shells comprising a material compatible with body fluids, the first shell comprising a first substantially straight peripheral wall portion and a second substantially straight peripheral wall portion adjacent the first substantially straight peripheral wall portion and being offset relative to the first substantially straight peripheral wall portion;  
       a battery enclosure comprising a cover and all or a portion of the first shell of the housing assembly, the cover of the battery enclosure disposed between the inner surfaces of the first and second shells, wherein the cover comprises a substantially straight peripheral wall portion and has a greater thickness dimension or a higher modulus of elasticity than the first shell, and an insulated electrical conductor sealingly coupled therethrough;  
       an electrochemical battery cell including an anode member, a cathode pellet and a liquid electrolyte disposed in the battery enclosure;  
       an operable electronic circuit electrically coupled to the electrochemical battery cell, electrically coupled to a medical electrical lead, and wherein said operable electronic circuit is mechanically coupled between the inner surface of the second shell and the cover of the battery enclosure and a majority of the operable electronic circuit is coupled to a deformable, flexible circuit substrate; and  
       a hermetic seal comprising a standing edge weld joint between the substantially straight peripheral wall portion of the cover and either the first or the second substantially straight peripheral wall portions of the first shell.